Thanks for all the replies guys, it's all very interesting.
Yep, I chose the Carbine kit for my GHK G5 over the DMR kit as I know I can buy outer barrel extensions or mock supressors if needed later on. In terms of regulating the FPS for when im changing barrels for something like the wide Orga Magnus 6.23, I may have to take out my 1 joule nozzel and put in the original factory nozzle in... or, GHK make the high power nozzle, which should get the fps to around 350, and if I install the single shot DMR trigger assembly adapter thing, sites should allow something like 400-450...I think.
from your comments I think I will need to stop using 0.25g, especially if I am going to attempt installing an R hop (ER hop is probably too much hop isnt it). I'll have to look at 0.30g BB's and above.
So to sum up the results from this topic/question, what do you make of my plans below.
Gun at the moment: GHK g5 currently with carbine extension kit and 1 joule nozzle (i have been told the NPAS/adjustable nozzle can cause fps inconsistency)
plans:
buy Orga 6.23 inner barrel, possibly 300-400mm length max, with outer barrel extension and maybe mock supressor. I will fit this and test it out with various BB weights, from 0.25g up to 0.40, and see how it goes, accuracy wise. I also put a little PTFE tape around my current inner barrel and will do on this Orga barrel as GHK owners may know, the barrel wobbles ever so slightly against the outer barrel, causing the BB's to go off to one or both sides at long range- with the heavy recoil etc- it helped me a lot.
If hop up could be improved, I will buy R hop kit, lengthen the window on the barrel etc....or get a good tech guy to do it properly, we'll see
during these tests I'll keep the FPS round the sweet spot for sites, 350 and if DMR 400 etc, changing the nozzles and trigger assembly
bam-